Definition
The rotating wheel-shaped component in a turbine engine that carries the turbine blades around its rim. The disc is mounted on the turbine shaft and spins at very high speed as hot exhaust gases strike the blades, transferring rotational energy to the shaft that drives the compressor and any accessory systems.
Plain English
A strong metal wheel inside a jet or turboprop engine. The turbine blades are attached around its outer edge, and the whole wheel spins when hot gases push against the blades.
Context Anchor
Seen in turbine engine construction, inspection, and maintenance discussions, especially when talking about turbine blades, shafts, cracks, heat damage, or engine overhaul.
Derivation
Turbine' comes from the Latin turbo, meaning 'spinning top' or 'whirlwind.' 'Disc' simply describes its flat, round shape. Together the words describe a flat wheel designed to spin under the force of moving fluid or gas.
Why Pilots Care
A cracked or unbalanced turbine disc can lead to blade separation and engine failure.
Analogy
Think of the turbine disc like a very strong wheel rim with blades fastened around its edge. The gas does not push the disc directly; it pushes the blades, and the blades turn the disc.
Intuition Check
Do not picture the visible fan at the front of a jet engine. A turbine disc is usually deeper inside the engine, in the hot turbine section, and it holds the blades that extract energy from the hot gas flow.
Example Sentence 1
During the inspection, the technician checked the turbine disc for cracks around the blade attachment slots.
Example Sentence 2
High-speed rotation requires the turbine disc to remain perfectly balanced.